The invention relates to a camshaft adjustment device comprising an electromagnetic actuator with an armature for actuating a hydraulic valve for camshaft adjustment, which armature can be adjusted axially along an adjustment axis. The camshaft adjustment device comprises fastening means for fastening the actuator on an engine element, particularly a housing element, for example a chain box or on the engine block. Furthermore, the invention relates to an internal combustion engine, particularly a motor vehicle internal combustion engine having one such camshaft adjustment device and an assembly method for a camshaft adjustment device. Camshaft adjustment devices for internal combustion engines have been known for a long time and are used for changing the relative angular position of the camshaft and therefore the camshaft with respect to the crankshaft of an internal combustion engine. The camshaft adjustment in this case takes place hydraulically, wherein the control of the pressure fluid takes place by means of a hydraulic valve, which can be actuated by means of an actuator comprising an armature that can be adjusted axially along an adjustment axis.
To fasten the actuator of the camshaft adjustment device on an engine element, it is known to use a screw connection, as is disclosed for example in DE 102 11 467 A1, DE 10 2007 019 923 A1 and DE 10 2006 031 517 A1. This installation is relatively complex and therefore comparatively expensive.
Therefore, camshaft adjustment devices that are simpler to install were developed by the applicant, as are described for example in DE 20 2010 007 406 U1. In the camshaft adjustment device presented there, the fastening means comprise a plurality of resilient elements arranged in a distributed manner over the circumference to form a plug-and-twist connection, in order to thus be able to install the actuator on an engine element in a simplified manner by means of a twisting movement.
A camshaft adjustment device is known from DE 10 2012 003 648 B3, in which the actuator is likewise fastened on an engine element in a plug-and-twist movement. It is disadvantageous in the known solution however that sufficient space must be kept free in the circumferential direction for realising the twisting movement for transferring the actuator to its installation position, which space cannot be used for arranging further functional parts. Furthermore, it is disadvantageous that the actuator of the known camshaft adjustment device can still be displaced out of its instillation position inadvertently by applying a sufficiently large de-installation force in the circumferential direction.
A stator unit for an electromagnetic camshaft adjustment device is known from DE 20 2011 050 746 U1, in which the electromagnetic actuator can be installed and de-installed in a combined plug-and-twist movement. In an installation position, it is possible to twist the electromagnetic actuator.
A camshaft adjustment device is known from DE 10 2010 012 917 A1, which can be installed and de-installed merely in a combined plug-and-twist movement, wherein it is possible to twist the actuator in an installation position. In one embodiment, the actuator is secured by means of a spring clip.
It is problematic for all camshaft adjustment devices in which the actuator is fastened on the engine element by means of a plug-and-twist movement that a sealing ring that is used and generally seals in the radial direction is loaded with force axially and in the circumferential direction (rotational movement) during installation, as a result of which the sealing ring is exposed to extreme forces, which can lead to premature damage of the sealing ring.
Furthermore, manual installation is inconvenient due to the high required forces.
A further problem exists in that known twist-and-plug connections are made more difficult due to the required loading of the sealing ring in the axial direction (excess pressures) and in the circumferential direction (rotational movement), as a result of which conventional o-rings cannot be used, rather special seals are used, using which an attempt it made to alleviate the above problems.